1. Field of the Invention
This invention relates to an organic ferromagnetic member having a spontaneous magnetization useful for such applications as recording media, temperature sensors, timers, magnetic shields, etc. as magnetic materials and a process for producing the same.
2. Related Background Art
So many magnetic members, that is, compounds having a ferromagnetism, are known. In compounds containing elements of the iron group and rare earth elements, that is, atoms having the d orbital and f orbital, a ferromagnetism due to the spin multiplicity is shown by degeneracy of d orbital electrons and f orbital electrons by electron spin &gt;1/2.
On the other hand, it is not known whether organic compounds composed of carbon holding electrons only in the p orbital as the main constituent element show a ferromagnetism. However, it is a recent trend to make ferromagnetic members from organic compounds and several attempts have been already made. For example, Obchinnikov et al disclosed that diacetylene polymers combined with a nitroso compound showed a ferromagnetism [Nature, 326, 370 (1987)]. It was disclosed also in Int. Conf. on Science and Technology of Synthetic Metals, June, 1988, Santa Fe, N. Mex.) that ferromagnetic polymers were formed by thermal decomposition of polyacrylonitrile.
Furthermore, Ohtani et al disclosed that ferromagnetic organic materials were obtained by photo-irradiation of condensation products of pyrenearomatic aldehyde (COPNA resin) together with a photosensitizer such as benzoquinone, etc. [Chemical Society of Japan, No. 57 Annual Meeting in Autumn, 3D410-3D413 (1988)].
However, these organic ferromagnetic members have such problems as poor reproducibility of their magnetization characteristics and complexity in their synthesis or treatments for the development of ferromagnetism.